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<h1>getBLI</h1>
<p class="purpose">Compute underlying Fourier band-limited interpolant (BLI).</p>

<h2>Syntax</h2>

<pre class="codeinput">
BLI = getBLI(func)
BLI = getBLI(func, dx)
BLI = getBLI(func, dx, sampling_factor)
BLI = getBLI(func, dx, sampling_factor, plot_BLI)
BLI = getBLI(func, [], [], plot_BLI)
[x_fine, BLI] = getBLI(func, dx, sampling_factor, plot_BLI)
...
</pre>

<h2>Description</h2>
<p><code>getBLI</code> computes the underlying band-limited interpolant (BLI) of a discretely sampled 1D function assuming a Fourier basis. The example below shows the BLI of a discrete spatial delta function.</p>

<pre class="codeinput">
delta = zeros(20, 1);
delta(end/2) = 1;
getBLI(delta, 0.001, 10, true);
</pre>

<img vspace="5" hspace="5" src="images/getBLI_01.png" style="width:560px;height:420px;" alt="">

<h2>Inputs</h2>

<table class="body">
    <tr valign="top">
        <td width = "150"><code>func</code></td>
        <td>1D input function</td>
    </tr> 
</table>

<h2>Optional Inputs</h2>

<table class="body">
    <tr valign="top">
        <td width = "150"><code>dx</code></td>
        <td>spatial sampling [m] (default = 1)</td>        
    </tr>     
	<tr valign="top">
        <td><code>upsampling_factor</code></td>
        <td>spatial sampling used to sample the underlying BLI (default = 20)</td>        
    </tr>     
	<tr valign="top">
        <td><code>plot_BLI</code></td>
        <td>Boolean controlling whether the discrete input function and its BLI are displayed (default = false)</td>        
    </tr>     
</table>

<h2>Outputs</h2>

<table class="body">
    <tr valign="top">
        <td width = "150"><code>BLI</code></td>
        <td>band-limited interpolant</td>
    </tr>
    <tr valign="top">
        <td><code>x_fine</code></td>
        <td>x-grid for BLI</td>
    </tr>    
</table>

<h2>See Also</h2>

<code><a href="spect.html">spect</a></code>

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